chore(pubspec.yaml): enhance project metadata and documentation

- Add version number 1.0.1
- Include project documentation URL
- Add project homepage URL
- Specify issue tracker URL
- Define relevant topics for better discoverability
- Improve description for better clarity

Author: fulleni

pubspec.yaml

@@ -1,8 +1,19 @@
 name: flutter_news_app_mobile_client_full_source_code
-description: Flutter News App - Mobile Client Full Source Code
-
+description: Complete, production-ready source code for a feature-rich Flutter news app mobile client.
+version: 1.0.1
 publish_to: none
 repository: https://github.com/flutter-news-app-full-source-code/flutter-news-app-mobile-client-full-source-code
+documentation: https://flutter-news-app-full-source-code.github.io/
+homepage: https://github.com/flutter-news-app-full-source-code/flutter-news-app-mobile-client-full-source-code
+issue_tracker: https://github.com/flutter-news-app-full-source-code/flutter-news-app-mobile-client-full-source-code/issues
+topics:
+  [
+    flutter-news-app,
+    flutter-news-app-mobile-client,
+    flutter-news-app-source-code,
+    flutter-news-app-sourcecode,
+  ]
+
 environment:
   sdk: ^3.9.0